JP3252037B2 - Bolt loosening structure and bolt loosening device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shaft part having a male thread on an outer periphery screwed into a screw hole provided in a mounting body, and the shaft part capable of holding an object to be fastened between the mounting body. And a device for loosening a bolt having an engagement portion provided at one end of the bolt.

[0002]

2. Description of the Related Art When an object to be fastened is firmly fastened to a mounting body using a bolt, it may be necessary to remove the bolt for disassembly, repair, or the like. ， The bolts may not be easily loosened due to seizure.

In this case, conventionally, a large loosening torque is applied to the bolt to loosen it, or if the bolt is not loosened yet, the head of the bolt is scraped off with a cutter or the like or burned off with a burner.

[0004]

However, according to the above-mentioned conventional method, not only is the work of loosening the bolt extremely troublesome, but also the work may be damaged by the work, and the fastening state is released. It may be necessary to repair the work later, or in some cases it may not be possible to reuse the work, resulting in lower work efficiency, higher costs, and waste of resources. Was.

The present invention has been made in view of the above circumstances, and provides a bolt loosening structure and a bolt loosening device which can easily and quickly perform a bolt loosening operation with a small loosening torque and solve the above problem. The purpose is to:

[0006]

In order to achieve the above object, a bolt loosening structure according to the present invention comprises: a shaft portion having an external thread on an outer periphery screwed into a screw hole provided in a mounting member; A bolt loosening structure for loosening a bolt having an engaging portion provided at one end of the shaft portion so that an object to be fastened can be sandwiched between the bolt and an axial end by opening an outer end at one end of the bolt. A blind hole having an inner end closing portion corresponding to the shaft portion is provided in the bolt, and the blind end of the blind hole is provided at an outer end of a shaft member inserted into the blind hole so that the inner end closing portion of the blind hole can be pressed. screwed into a female screw provided on the outer end
A first feature is that an auxiliary bolt that can be screwed in is connected from the outside of the bolt, and a sphere made of a rigid material is interposed between the inner end of the shaft member and the inner end closed portion of the blind hole. The second feature is that operating members for screwing operation are provided at both ends of a rod-shaped auxiliary bolt having a male screw screwed to a female screw of a blind hole on an outer periphery over the entire length in the axial direction. Even if the auxiliary bolt is screwed into the female screw until one end of the auxiliary bolt faces the outer end of the shaft member, the shape of the one end of the auxiliary bolt and the shape of the shaft member are avoided so as to avoid contact with the outer end of the shaft member. Length is determined,
The third end of the auxiliary bolt is provided with a contact surface that comes into contact with the outer end of the shaft member when the auxiliary bolt is screwed into the female screw with the other end facing the outer end of the shaft member. And the screws of said bolts and auxiliary bolts
The fourth feature is that the tightening directions are different from each other.
I have.

Further, the bolt loosening device of the present invention is arranged such that an object to be fastened can be clamped between a shaft portion having an external thread which is screwed into a screw hole provided in the mounting member and the mounting member. And an engaging portion integrally connected to one end of the portion, and a blind hole extending in the axial direction with an outer end opened at the engaging portion has an inner end closing portion corresponding to the shaft portion. in the bolt loosening device for loosening the set is the bolt, relative axial immovable from its side against the engaging portion of the bolt 且
And a support engaged non-rotatably with this support.
Movably supported and extending radially outwardly of the bolt
An operating arm inserted into the blind hole and an inner end closing portion of the blind hole
A shaft member , one end of which is in contact with the shaft, and the engaging portion of the support
In the middle of the operating arm corresponding to the blind hole
Movably connected so that the tip engages the other end of the shaft member.
And a pressing pin for obtaining the engagement state.
In conjunction with the operation of pushing down the operation arm to the bolt side,
It is characterized in that the shaft member is pressed toward the inner end closing portion side of the blind hole .

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

[0009] First, in FIG. 1 showing a first embodiment of the present invention, the bolt B ₁ represents the base end of the shaft portion 2 having at least the leading end side outer circumference an external thread 1 is integrally connected to the engaging portion 3 ₁ made are those, the engaging portion 3 _1, an engagement operation portion 4 formed in its cross-section substantially regular hexagons rotation operation tool such as a spanner as engageable shaft portion 2 side of the engaging operation part 4 And a flange portion 5 protruding outward from the end.

[0010] are those fastened object 6 is fastened to the mounting member 7 by the bolt B _1, screw holes 8 in the attachment body 7
It is provided, on the fastened object 6, insertion holes 9 for inserting the shaft portion 2 of the bolt B ₁ is provided. By tightening the Thus was male screw 1 inserted through the shaft portion 2 into the insertion hole 9 is screwed into the threaded hole 8, the fastened object 6, between the engaging portion 3 ₁ and the mounting body 7 of the bolt B ₁ in Thus, the object 6 is fastened to the attachment 7.

[0011] the bolt B ₁ represents, blind hole 10 of the inner end closure 10a is made to correspond to the shaft portion 2 with the outer end by opening extending in the axial direction is provided on the engaging portion 3 _1,該盲hole the 10, the shaft member 11 ₁ made of rigid material is inserted the inner end to the inner end closed portion 10a as can abut, the shaft member 11 ₁
The outer end of is coaxially connected to the and integrally with the auxiliary bolt 13 ₁ screwed into a female screw 12 provided in the outer end of the blind hole 10.

[0012] With such a structure, when the bolt B ₁ is not easily come loose in normal release torque due to such with rust with or burn of the male screw 1 is also relatively easily and quickly with a small release torque bolt B ₁ it is possible to loosen the.
That is, by threadedly advancing operation of the auxiliary bolt 13 _1, the inner end of the shaft member 11 ₁ is integral with the bolt 13 ₁ presses the inner end closure 10a of the blind hole 10. As a result, the bolt B ₁
A portion corresponding to the shaft member 11 ₁ can cause elongation deformation in the axial direction, or the engaging portion 3 ₁ of the bolt B ₁ is to lower the clamping force on the fastened object 6 (i.e. compression force) it can.

[0013] threaded for this result, the frictional force acting between the flange portion 5 and the fastened object 6 in the engaging portion 3 ₁ of the bolt B _1, and a threaded hole 8 of the shaft portion 2 and the mounting body 7 of the bolt B ₁ will be the frictional force acting on the engaging portion is reduced, it is possible to loosen the bolt B ₁ easily even at relatively small release torque. Thus the loosening of the bolt B _1, without damaging the fastened object 6 during the work, it is possible to perform easily quickly.

[0014] Then the tightening force of the bolt B _1, the relationship between the amount of deformation of the bolts B ₁ and the fastened object 6 accompanying the tightening,
This will be described with reference to the graphs shown in FIGS. For example in the case of tightening the bolt B ₁ in clamping force Ff, elongation λt the bolt B _1, the shrinkage of λc in the fastened object 6 is assumed to occur, respectively, this relationship of (a) and FIG. 2 (b) Respectively. By the way, the tightening force Ff acts on the bolt B ₁ as a tensile force, whereas
The object 6 acts as the same compressive force as the tensile force, and the point of the tensile force Ff in FIG. 2A and the point of the compressive force Ff in FIG. Together, the tightening diagram of FIG. 3 is obtained.

In the tightening diagram of FIG. 3, the tightening force Ff
The shaft member 11 in the inner end closure 10a of the blind hole 10 in the bolt B ₁ in a state in which tightened the aid bolt 13 _1
When a pressing force of Wa is applied through the shaft member 1, the shaft member 1
If 1 ₁ volt B ₁ at portions corresponding to is to be caused to extend only in the axial direction lambda, so that the pressing force Wa is added Ft becomes tensile force to the bolt B _1, acting on the bolt B ₁ The total tensile force is (Ff + Ft). On the other hand, the compression force Fc is lost from the workpiece 6 and the total compression force acting on the workpiece 6 becomes (Ff-Fc). Because Thus to said total compressive force (Ff-Fc) is equivalent to clamping force on the fastened object 6 of the bolt B _1, the tightening force of the bolt B ₁ represents,
It decreases by F _c by pressing the inner end closure 10a of the blind hole 10 through the shaft member 11 ₁ in the auxiliary bolt 13 _1.

By the way, the tightening diagram of FIG. 3 shows a case where the pressing force Wa by the auxiliary bolt 13 ₁ stays within the elastic range of the bolt B ₁ , while FIG. 4 shows a case where it extends over the plastic range. And the inner end closing portion 10a of the blind hole 10
In the auxiliary bolt 13 ₁ when allowed to act a pressing force of Wa via the shaft member 11 _1, the bolt B ₁ at a portion corresponding to the shaft member 11 ₁ is to be caused to extend in the axial direction by lambda ' , the pressing force Wa is Ft bolts B ₁ 'becomes adding a tensile force becomes the total tensile force acting on the bolt B ₁ represents (Ff + Ft' becomes). On the other hand, the compression force Fc is lost from the workpiece 6 and the total compression force acting on the workpiece 6 becomes (Ff-Fc '). Because Thus to said total compressive force (Ff-Fc ') corresponds to the clamping force on the fastened object 6 of the bolt B _1, the tightening force of the bolt B ₁ represents,
F _c ′.

[0017] As is apparent from this FIG. 3 and FIG. 4, when in its elastic range and plastic region in the bolt B ₁ and allowed to act the same pressing force Wa, respectively, decrease the tightening force of the bolt B ₁ associated therewith the amount is in the elastic range 'is intended to be, Ri, Fc <Fc' Fc in Fc, plastic zone because it is, the pressing force Wa of the auxiliary bolt 13 ₁ acts more effectively in the way of plastic region become.

[0018] Note that as shown in FIG 3, when the elongation deformation of the bolt B ₁ by tightening of the auxiliary bolt 13 ₁ is still remains in the elastic region is capable of re-use of the bolt B _1.

FIG. 5 and FIG. 6 show the fastening object 6 of the bolt B ₁ .
Is a graph showing, based on experimental data, the relationship between the tightening force and the tightening torque and the loosening torque exerted on the tire.
Figure 5 whereas the bolt B ₁ and the auxiliary bolt 13 ₁ are both show the case of a right-hand thread, 6 volts B ₁ is right-hand thread, the auxiliary bolt 13 ₁ indicates a case of left-hand thread.
The 5 and 6, (a) shows the relationship between the tightening torque and the tightening force of the bolt B _1, (b) is out of the blind bore 10 by tightening state of the bolt B ₁ tightening of the auxiliary bolt 13 ₁ The relationship between the tightening torque of the auxiliary bolt 13 ₁ and the decrease in the tightening force of the bolt B ₁ when the end closing portion 10a is pressed by the shaft member 11 ₁ is shown. shows the relationship between the clamping force and the loosening torque when loosening the B _1. Moreover the experimental data of FIG. 5 and 6, all but tightening direction of the auxiliary bolt 13 ₁ is obtained by an experiment identical conditions.

According to the above experimental results, while the tightening torque was 14.6 kgfm, the auxiliary bolt 1
When ₁ is a right-hand thread (Fig. 5), the loosening torque is 1
0.4 kgf · m, and the addition when the auxiliary bolt 13 ₁ and the left-handed screw (Fig. 6), the release torque is 8.8 kgf ·
m. Therefore, bolt B ₁ and auxiliary bolt 1
3 person having different _first screw tightening direction (FIG. 6) it can be seen that could loosen the bolt B ₁ with smaller release torque.

FIG. 7 shows a second embodiment of the present invention, the blind hole 10 of the bolt B ₁ represents, its inner end closed portion 10a
Shaft member 11 ₂ made of a rigid material so that the inner end can contact the
There is inserted, the auxiliary bolt 13 ₂ and the shaft member 11 ₂ is another body, it is screwed into the internal thread 12 of the outer end portion of the blind hole 10 so as to face the outer end of the shaft member 11 _2.

According to the second embodiment, the auxiliary bolt 1
3 blind holes 10 in the inner end of the shaft member 11 ₂ by ₂ screwing operation
Inner end closure 10a can be pressed in, thereby the bolt B _1, causing the portion corresponding to the shaft member 11 ₂ in the axial direction of the elongation deformation, loosening the bolts B ₁ with a relatively small release torque Becomes possible. Moreover, the auxiliary bolt 13
Because ₂ is intended to sliding contact with the outer end of the shaft member 11 _2, the shaft member 11 ₁ to the auxiliary bolt 13 ₁ as in the first embodiment
Not only can prevent the occurrence of cracks and the like caused by the application of a large torsional force to the connecting portion when the members are integrally connected, but also the shaft member 1 made of a highly rigid material.
To 1 _2, it is possible to facilitate the processing of the threaded or the like to form a relatively soft material the auxiliary bolt 13 _2.

[0023] FIG. 8 shows a third embodiment of the present invention, the shaft member 11 ₂ inserted into the blind hole 10 of the bolt B ₁
A sphere 14 made of a rigid material is interposed between the inner end of the blind hole 10 and the inner end closing portion 10a of the blind hole 10.

According to the third embodiment, to reduce the inner end of the shaft member 11 _2, a rotational friction force caused by the screwing of the auxiliary bolt 13 ₁ between the inner end closure 10a of the blind hole 10 can be, thereby it is possible to further reduce the release torque of the bolt B _1, it is possible to prevent the cracks in the shaft member 11 ₂ with the torsion due to rotational friction.

It should be noted, may be sphere 14 is interposed between the inner end of the shaft member 11 ₁ shown in FIG. 1, the inner end closed portion 10a of the blind hole 10.

FIG. 9 and FIG. 10 shows a fourth embodiment of the present invention, opposite the outer end of the shaft member 11 ₂ inserted into the blind hole 10 in the bolt B _1,該盲hole 10 auxiliary bolt 13 ₃ into the internal thread 12 of the outer end of is screwed.

[0027] The auxiliary bolt 13 _3, the female screw 12
The external thread 15 screwed into having the outer periphery over the entire axial length is intended to be formed in a rod shape, the both ends of the auxiliary bolt 13 _3, in order to enable fitting a turning tool (not shown) for example cross The operation part 16, as a hexagonal concave part,
17 are provided respectively.

Further, as shown in FIG.
₃ the shaft member 1 is also screwed to the female screw 12 to screwing completed with its one end facing the outer end of the shaft member 11 ₂
So as not to the outer end of 1 ₂₂ abuts against the auxiliary bolt 13 _3, the depth and length of the shaft member 11 and _second operation section 16 provided as a recess at one end of the auxiliary bolt 13 ₃ is defined. In contrast, closed end of the operation portion 17 provided at the other end of the auxiliary bolt 13 ₃ functions as a shaft member 11 _{and second} contact to the outer end can contact surface 18. That is, as shown in Figure 10, the auxiliary bolt 13 ₃ other end the shaft member 11 ₂
Contact surface 18 when screwed into the female thread 12 in the opposite state to the outer end of the depth of the recess in which the operation unit 17 so as to contact the outer end of the shaft member 11 ₂ is determined.

According to the fourth embodiment, the bolt in the state where the engagement by B ₁ to the mounting member 7 fastened object 6, as shown in Figure 9, the auxiliary bolt 13 of ₃ to one end side operation unit 1
6 so as to face the outer end of the shaft member 11 ₂ female 1
Screw it into 2. Then, the auxiliary bolt 13 ₃
Since there is no possibility that even an auxiliary bolt 13 ₃ contacts the shaft member 11 ₂ by screwing, pressing force from the shaft member 11 ₂ on the inner end closure 10a of the blind hole 10 does not act. Also when removing the fastened object 6 by loosening the bolts B ₁ represents, by loosening the auxiliary bolt 13 ₃ Once tightened abutment surface 18 so as to face the outer end of the shaft member 11 _{and second} support bolt 13 ₃ again. Then, the abutment surface 18 by threadedly advancing operation of the auxiliary bolt 13 ₃ comes into contact with the outer end of the shaft member 11 _2, push the inner end closure 10a of the blind hole 10 from the auxiliary bolt 13 ₃ via the shaft member 11 ₂ since the pressure acts, it is possible to loosen the bolt B ₁ a relatively small release torque.

FIG. 11 shows a fifth embodiment of the present invention, in which a male screw 1 screwed into a female screw 12 at the outer end of a blind hole 10 is provided.
5 at one end of the auxiliary bolt 13 ₄ has the outer periphery over the entire axial length are formed in a rod shape is provided an operation unit 16,
At the other end of the auxiliary bolt 13 _4, together can abut a flat abutment surface 20 is provided on the outer end of the shaft member 11 _2, which can engage a rotation operation tool such as a driver "+" shape, or An operation unit 19 that is a "-"-shaped groove is provided.

[0031] The fifth embodiment also, the operation unit 16 of the one end of the auxiliary bolt 13 ₄ while fastening the mounting member 7 fastened object 6 by a bolt B ₁ is opposed to the outer end of the shaft member 11 ₂ by keeping screwed to the female screw 12 as accidentally be screwed auxiliary bolt 13 ₄ auxiliary bolt 13 ₄ are not the bolt B ₁ is loosened so does not contact the shaft member 11 _2, also auxiliary bolt 13 ₄ once loosened, by to tightening the auxiliary bolt 13 ₄ again to face the contact surface 20 is the outer end of the shaft member 11 _2, those abutment surfaces 20 on the outer end of the shaft member 11 ₂ by contact via the shaft member 11 ₂ from the auxiliary bolt 13 ₄ can exert a pressing force on the inner end closure 10a of the blind hole 10, it is possible to loosen the bolt B ₁ a relatively small release torque .

FIG. 12 shows a sixth embodiment of the present invention, in which a male screw 1 screwed into a female screw 12 at the outer end of a blind hole 10 is shown.
5 at one end of the auxiliary bolt 13 ₅ has the outer circumference over the entire axial length are formed in a rod shape is provided an operation unit 16,
Auxiliary bolt 13 to the other end of the _5, the operation portion 2 having a can abut a flat abutment surface 22 a protruding end to the outer end of the shaft member 11 ₂
The operating portion 21 is formed, for example, in a regular hexagonal cross section so that a tool such as a spanner can be engaged with the operating portion 21.

According to the sixth embodiment, the auxiliary bolt 1
3 by the operation unit 16 of ₅ the one end kept screwed into the internal thread 12 so as to face the outer end of the shaft member 11 _2, also screwed auxiliary bolt 13 ₅ erroneously bolt B ₁
Abutment surface 22 is not loosen, also the auxiliary bolt 13 ₅
By There tightening again reversed so as to face the outer end of the shaft member 11 _2, via the shaft member 11 ₂ from the auxiliary bolt 13 ₅ an abutment surface 22 is abutted against the outer end of the shaft member 11 ₂ can act a pressing force to the inner end closure 10a of the blind hole 10, it is possible to loosen the bolt B ₁ a relatively small release torque.

FIG. 13 shows a seventh embodiment of the present invention, in which the male screw 1 screwed into the female screw 12 at the outer end of the blind hole 10 is shown.
The 5 has the outer periphery over the entire axial length at one end portion of the auxiliary bolt 13 ₆ formed in a rod shape "+" shape or "-"
An operating portion 19, which is a groove of a shape, is provided, and an auxiliary bolt 13 ₆
The other end portion, an operation portion 21 having a contact capable flat abutment surface 22 on the projecting end to the outer end of the shaft member 11 ₂ is projected.

[0035] While one end of the auxiliary bolt 13 ₆ of which are formed on a flat surface, also screwed to the female screw 12 to the screw-completed state of the auxiliary bolt 13 ₆ at one end opposite the outer end of the shaft member 11 ₂ the outer end of the shaft member 11 ₂ is the length of the shaft member 11 ₂ so as not to abut against the auxiliary bolt 13 ₆ is defined.

[0036] The seventh embodiment also, the third, fourth, similarly to the fifth and sixth embodiments, the operation unit 19 of the one end of the auxiliary bolt 13 ₆ in the engaged state of the fastened object 6 axes by keeping screwed into the internal thread 12 so as to face the outer end of the member 11 _2, since no auxiliary bolt 13 ₆ also screwed auxiliary bolt 13 ₆ accidentally comes into contact with the shaft member 11 _2, bolts never B ₁ is loosened, also loosen the auxiliary bolt 13 ₆ once the abutment surface 22 is the shaft member 11 ₂
Of By so as to face tighten the auxiliary bolt 13 ₆ again at the outer end, via the shaft member 11 ₂ from the auxiliary bolt 13 ₆ the abutment surface 22 is abutted against the outer end of the shaft member 11 ₂ blind hole A pressing force can be applied to the inner end closing portion 10a of the bolt ₁₀ , and the bolt B1 can be loosened with a relatively small loosening torque.

[0037] FIG. 14 shows an eighth embodiment of the present invention, the bolt B ₂ is for one end of the shaft portion 2 'nut as an engaging portion 3 ₂ consisting screwed, shaft part 2 'at one end periphery of the male screw 23 screwing the engaging portion 3 ₂ is engraved, the shaft portion 2' to the other end periphery of the screw hole 8 of the mounting body 7
The male screw 1 to be screwed is formed.

[0038] The shaft portion 2 'of the bolt B _2, one end blind hole 10 the outer end by opening extending in the axial direction is provided on, the該盲hole 10, the inner to its inner end closed portion 10a is inserted the shaft member 11 ₁ made of a rigid material the end as possible contact, the outer end of the shaft member 11 _1, the auxiliary bolt 13 ₁ screwed into a female screw 12 provided in the outer end of the blind bore 10 Are integrally and coaxially connected.

Also in the eighth embodiment, the auxiliary bolt 13 ₁ is tightened with the object 6 fastened to the mounting body 7 by the bolt B ₂ , and the inner end closing portion of the blind hole 10 is removed from the shaft member 11 _1. by applying a pressing force to 10a, it is possible to loosen the engagement member 3 ₂ with a relatively small release torque.

FIGS. 15 , 16 and 17 show a ninth embodiment of the present invention, in which parts corresponding to the above-described embodiments are denoted by the same reference numerals.

[0041] In the bolt B ₆ to fasten the mounting member 7 fastened object 6, the engaging portion 3 ₆ provided integrally with the shaft portion 2 so as to sandwich the fastened object 6 between the mounting member 7, An engaging operation portion 4 formed in a regular hexagonal cross section and a flange portion 5 for holding the workpiece 6 between the mounting member 7 and the engaging operation portion 4 have a circular cross section having a smaller diameter than the engaging operation portion 4. It is provided continuously through a neck 42. Bolt loosening device 24 ₅ for loosening the bolt B ₆ also comprises a support body 25 ₅ which is detachably mounted to the engaging portion 3 ₆ of the bolt B _6, as can press the inner end closure 10a of the blind hole 10 It includes a shaft member 11 ₂ to be inserted into blind hole 10, and a pressing means 26 ₂ provided a shaft member 11 ₂ on the side for pressing the inner end closure 10a of the blind hole 10 in the support 25 ₅ as possible pressing.

[0042] The support 25 _5, the engaging portion of the bolt B ₆ 3 ₆
Engagement operation portion and the first engagement attachment portion 43 from the side of the engageable substantially U-shaped in 4, substantially in the neck portion 42 engageable from the side of the engaging portion 3 ₆ of the bolt B ₆ U in it is intended and a second engagement attachment portion 44 shaped as shown in Figure 17, the engaging portion 3 ₆ of the bolt B ₆ is attachable from the side. That relative rotation of the support 25 ₅ for the bolt B ₆ is prevented by the engagement of the engaging operation part 4 of the first engagement attachment portion 43, by the engagement of the second engagement attachment portion 44 of the neck 42 relative axial movement of the support member 25 ₅ with respect to the bolt B ₆ is prevented.

The pressing means 26 _2, bolt B with proximal the shaft 45 perpendicular to the shaft member 11 _second axis that is inserted into blind hole 10 is swingably carried on a support 25 _5
6 , an operation arm 46 extending outward in the radial direction,
Operated with the support 25 ₅ is attached to the engaging portion 3 ₆ of the bolt B ₆ at the portion corresponding to the blind hole 10 of the bolt B ₆ arm 4
6 is provided with a pressing pin 48 connected via a shaft 47 to an intermediate portion.

[0044] In Thus, in a state where the support 25 ₅ is attached to the engaging portion 3 ₆ of the bolt B _6, and insert the push pin 48 into the blind hole 10, the pressing pin by depressing the operating arm 46 48 in can act a pressing force to the shaft member 11 _2.

According to the ninth embodiment, too, the shaft member 11 ₂
In this state, the bolt B ₆ can be elongated and deformed, and in this state, the support arm 25 ₅
The by rotating operation, it is possible to loosen the bolt B ₆ with a relatively small release torque.

Although the embodiments of the present invention have been described in detail, the present invention is not limited to the above embodiments, and various design changes can be made without departing from the present invention described in the appended claims. It is possible to do.

[0047]

As described above, in the bolt loosening structure according to the first aspect, the blind hole having the outer end opened at one end of the bolt and extending in the axial direction and the inner end closing portion corresponding to the shaft portion is formed by the bolt. The inner end of the blind hole can be pressed against the outer end of a shaft member that can be pressed into the blind hole, and the outer end of the bolt is screwed into a female screw provided at the outer end of the blind hole. Than
Since the auxiliary bolts which can be squeezed are connected, a pressing force is applied to the shaft members by tightening the auxiliary bolts, thereby causing the bolts to expand and deform at the portions corresponding to the shaft members, thereby producing a relatively small torque. The bolt can be loosened. Especially when giving elongation deformation to bolts
Simply screw the auxiliary bolt directly into the blind hole of the bolt
Pressure means using a pressurized fluid inside and outside the bolt.
Because there is no need to provide specially, it is used for supplying and discharging pressurized fluid.
Pumps, pipes, hoses, etc. are no longer required
It can greatly contribute to the reduction of equipment costs and the mobility
Very good and relatively small bolt loosening work
Can be performed easily and accurately in a compact work space.
The surrounding area (for example, by tightening the auxiliary bolt)
If the surface of the workpiece is damaged or dented,
Absent.

According to the second aspect of the present invention, in addition to the configuration of the first aspect, a sphere made of a rigid material is interposed between the inner end of the shaft member and the inner end closed portion of the blind hole. As a result, the rotational friction force between the inner end of the shaft member and the closed end of the blind hole can be reduced, and the bolt loosening torque can be further reduced. Thus, it is possible to prevent the shaft member from being cracked.

According to the third aspect of the present invention, in addition to the configuration of the first or second aspect of the present invention, a male screw which is screwed into the female screw of the blind hole is formed in a rod shape on the outer periphery over the entire length in the axial direction. Operation parts for screwing operation are provided at both ends of the auxiliary bolt. The auxiliary bolt is screwed into the female screw until one end of the auxiliary bolt is completely screwed into the female screw with one end facing the outer end of the shaft member. The shape of one end of the auxiliary bolt and the length of the shaft member are determined so as to avoid contact with the end, and the other end of the auxiliary bolt is connected to the other end of the auxiliary bolt facing the outer end of the shaft member. Since a contact surface is provided for contacting the outer end of the shaft member when screwed into the female screw, the auxiliary bolt should be arranged so that one end thereof faces the outer end of the shaft member when the bolt is tightened. By mistake, bolt It is possible to prevent loosening.

According to the fourth aspect of the present invention, the bolt
Since the screw tightening directions of the
The bolt can be loosened with a relatively small loosening torque.

Further, the bolt loosening device according to claim 5 is
Against the engaging portion of the bolt relative axial immovable from its side
And a support engaged in such a way that it cannot rotate relative to the support.
It is swingably supported and extends outward along the radial direction of the bolt.
Operating arm and the inner end of the blind hole inserted into the blind hole of the bolt
A shaft member having one end abutting on the closing portion, and the engagement between the shaft member and the support member;
Swings to the middle part of the operating arm corresponding to the blind hole in the engaged state
Is connected to the shaft so that the tip can engage with the other end of the shaft member.
Pressure pin , so that the support arm is engaged with the bolt engagement portion and the operation arm is pushed down to the bolt side.
Dynamic and to so that by the action of pressing force can Rukoto cause deformation extends to bolt the shaft member, by turning operation of the left operating arm in that state, by loosening the bolts with a relatively small torque Becomes possible. Especially elongation deformation of bolt
When providing support, the support is engaged with the bolt engagement part.
And press the pressing pin against the outer end of the shaft member in the bolt blind hole.
Simply press down the operation arm in the
It is not necessary to provide special pressurizing means using bolts inside and outside the bolt.
Pumps, pipes, and hoses for supplying and discharging pressurized fluid
Large cost savings on equipment as a whole
As well as very good mobility.
Above, easy bolt loosening work in a relatively small work space
And can be performed accurately, and tightening of auxiliary bolts
The surrounding area (eg, the surface of the workpiece)
There is no danger of damaging or denting. Also above support
The link mechanism consisting of the body, the pressing pin and the operating arm
Can be used for both forced elongation means and screwing operation means.
Therefore, the structure of the device can be simplified and the cost can be reduced.
Reduction is achieved.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a first embodiment.

FIGS. 2A and 2B are graphs showing a relationship between a force applied to a bolt and an object to be fastened when the bolt is tightened and an amount of deformation thereof, wherein FIG. 2A is a diagram corresponding to the bolt and FIG. It is.

FIG. 3 is a tightening diagram when a pressing force of an auxiliary bolt is applied to the bolt within its elastic range.

FIG. 4 is a tightening diagram when a pressing force of an auxiliary bolt is applied over a plastic region of the bolt.

FIG. 5 is a graph showing experimental data (when the bolt and the auxiliary bolt are right-handed screws) on the relationship between the tightening force of the bolt and the tightening torque and the loosening torque.

FIG. 6 is a graph showing experimental data (when the bolt and the auxiliary bolt are left-handed screws) regarding the relationship between the bolt tightening force and the tightening torque and the loosening torque.

FIG. 7 is a longitudinal sectional view of the second embodiment.

FIG. 8 is a longitudinal sectional view of a third embodiment.

FIG. 9 is a vertical sectional view of the fourth embodiment, showing a bolt tightened state.

FIG. 10 is a sectional view corresponding to FIG. 9 and showing a bolt loosened state.

FIG. 11 is a longitudinal sectional view of a fifth embodiment.

FIG. 12 is a longitudinal sectional view of a sixth embodiment.

FIG. 13 is a longitudinal sectional view of the seventh embodiment.

FIG. 14 is a longitudinal sectional view of the eighth embodiment.

FIG. 15 is a longitudinal sectional view of the ninth embodiment.

16 is a view taken in the direction of the arrow 16 in FIG.

FIG. 17 is a cross-sectional view showing a state before the support is attached to the bolt .

[Explanation of symbols]

1,15 ... male screw 2,2 '... shaft portion 3 _1, 3 _{2, 3} 3, 3 _4, 3 _5, 3 ₆ ... engaging portion 6 ... fastened object 7 ... mounting body 8 ... screw hole 10 ... blind hole 10a ... inner end closing portion 11 _1, 11 _2, 11 ₃ ... shaft member 12 ... female screw 13 _1, 13 _2, 13 _3, 13 _4, 13 _5, 13 ₆ ...
・ Auxiliary bolt 14 ・ ・ ・ 14 16, 17, 19, 21 ・ ・ ・ Operation part 18, 20, 22 ・ ・ ・ Contact surface 24 ₁ , 24 ₂ , 24 ₃ , 24 ₄ , 24 ₅・ ・ ・ Bolt loosening 25 _1, 25 _2, 25 _3, 25 _4, 25 ₅ ... support 26 _1, 26 ₂ ... pressing means 34, 46 ... operating arm B _1, B _2, B _3, B _4, B _5, B ₆ ··· bolt

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Haruyuki Watanabe 238 Nakaya Higashi, Gifu City, Gifu Prefecture (72) Inventor Manabu Naoi 3-7, Sohara Shineimachi, Kakamigahara City, Gifu Prefecture (56) References JP-A-5-118314 (JP, A) JP-A-63-89233 (JP, A) JP-A-6-159341 (JP, A) JP-A-56-143613 (JP, U) (58) Fields investigated (Int. Cl. ⁷⁾ , DB name) F16B 31/04 F16B 35/00

Claims (5)

(57) [Claims] 1. A shaft (2, 2 ') having an external thread (1) on an outer periphery for screwing into a screw hole (8) provided in a mounting body (7), and the mounting body (7). A bolt (B) having an engaging portion (3 ₁ , 3 ₂ ) provided at one end of the shaft portion (2, 2 ′) so as to be able to clamp the work (6) therebetween.
_1, B in the bolt loosening structure to loosen _2), bolts (B _1, B ₂₎ the shaft portion inner end closure of (10a) with one end extending in the axial direction by opening the outer end in the (2) Blind holes (10) corresponding to the bolts (B ₁ ,
B ₂ ), the inner end closing portion (10) of the blind hole (10).
a) can be pressed and screwed into a female screw (12) provided at the outer end of the shaft member (11 ₁ , 11 ₂ ) inserted into the blind hole (10). Said bol
Preparative (B _1, B ₂₎ screwing operation of auxiliary bolts from the outside of the (13 _1, 13 _2, 13 _3, 13 _4, 13 _5, 13
₆ ) A bolt loosening structure characterized in that the bolts are connected. 2. A sphere (14) made of a rigid material is interposed between an inner end of the shaft member (11 ₂ ) and an inner end closing portion (10a) of the blind hole (10). Item 1. A bolt loosening structure according to Item 1. 3. An auxiliary bolt (13 ₃ , 13 ₄ , 13 ₅ , 13, 13
13 at both ends of the _6), the operation portion for screwing operations (16,17,19,21) are respectively provided, an auxiliary bolt (13 _3, 13 _4, 13 _5, 13 ₆₎ One end of the shaft a The shaft member (11) may be screwed into the female screw (12) in a state facing the outer end of the member (11 ₂ ) until screwing is completed.
₂ ) Make sure that the auxiliary bolts (13
_3, 13 _4, 13 _5, 13 one end portion shape and length of the shaft member (11 ₂₎ is defined in _6), an auxiliary bolt (13 _3,
13 _4, 13 _5, 13 ₆ to the other end of) the state where the auxiliary bolt (13 _3, 13 _4, 13 _5, 13 ₆₎ the other end opposite the outer end of the shaft member (11 ₂₎ Female screw (1
3. The bolt loosening structure according to claim 1, wherein a contact surface (18, 20, 22) is provided which comes into contact with an outer end of the shaft member (11 ₂ ) when screwed into the second member. 4. The bolt (B ₁ , B ₂ ) and an auxiliary bolt
Doo _{(131-134 6)} screw tightening different directions of
The button according to claim 1, 2, or 3, wherein
Loosen structure. And 5. Preparative with body shank with the outer circumference an external thread (1) to be screwed into the threaded hole (8) provided in (7) (2), between the mounting member (7) Work to be fastened (6)
Provided with a said shaft portion (2) engaging portions which are integrally connected to one end of the (3 ₆₎ as possible clamping, engaging portion (3
_A blind hole (10) extending in the axial direction with an outer end opened at ₆ ) is used to loosen a bolt (B ₆ ) drilled at the inner end closing portion (10a) corresponding to the shaft portion (2). the axis of the bolt loosening device, from the engaging portion (3 ₆₎ against the side of the bolt (B ₆₎
(25 ₅ ) engaged in a direction incapable of relative movement and relative rotation, and a bolt rotatably supported by the support (25 ₅ ).
An operation arm (46) extending outward in the radial direction of (B ₆ )
When the inner end closed blind hole is inserted in (10)該盲hole (10)
A shaft member (11 ₂ ) whose one end can contact the closing part (10a )
When the support member (25 ₅₎ the engaging portion (3 ₆₎ engaging into shaped
Between the operating arms (46) corresponding to the blind holes (10)
Part is swingably connected to the shaft member, and the tip is the shaft member (1).
1 ₂₎ and a pressing pin (48) that can engage the other end of the pressing pin (48) is in the engaged state, the operating arm
(46) interlocks with the operation of pushing down to the bolt (B ₆ ) side.
And the shaft member (11 ₂ ) is closed at the inner end of the blind hole (10).
(10a) A bolt loosening device characterized by pressing to the side .